Lightweight container



Oct. 11, 1949. LA VERNE E- CHEYNEY ETAL 2,484,608

I LIGHT-WEIGHT CONTAINER Filed NOV. 30, 1945 IN V EN TOR.

Patented Oct. 11, 1949 LIGHTWEIGHT CONTAINER La. Verne E. Cheyney and Robert J. McCutcheon,

Akron, Ohio, assignors to Wlngfoot Corporation, Akron, Ohio, a corporation oi. Delaware Application November 30, 1945, Serial No. 631,864

' 1 Claim. (01. 229-14) This invention relates to a hollow, reuseable container of extremely light weight for the shipping and storage of perishable items; such as foods, flowers, medicines, etc., which are to be maintained at a low temperature for considerable periods of time. The container consists entirely of rubber hydrochloride film and lightweight insulating material. The insulating material is sealed in the rubber hydrochloride film.

The container of such construction may vary over wide limits in shape and design. It may be reinforced by suitable construction materials, such as cardboard, wires. and the like. The preferred container of this invention is an unreinforced container, cylindrical in shape, and having an interior volume somewhere between that of a pint and a gallon. The container may be designed to be collapsible and thus easily returnable although the preferred form of the container is not so constructed.

A cylindrical container is preferred because the surface is less than that of a rectangular container of the same volume, and the surface where radiation may occur is correspondingly less. If a large number of containers of the same size is to be shipped at one time, a. rectangular container may be preferred to economize space. The shape of the article to be shipped may determine the shape of the container to be used. Cylindrical containers and containers of any shape and design may be employed. The container as described may be slipped into a snugly fitting cardboard or other rigid container or used in any other desired manner.

The accompanying drawing shows a cylindrical container of the type described. The body of the container and the cover are somewhat removed from one another in order to clearly illustrate the invention. The body I is formed of the insulating material 2 which gives form to the container and is covered by the rubber hydrochloride film 3. The top of the container is countersunk to receive the cover I which is similarly protected by insulation 5. The depending flange 6 of the cover fits over the outside of the top of the side wall I, made rigid by the union of inner and outer covering plies of rubber hydrochloride film 8. The film used may be about .002 inch thick. Thinner film may be used where satisfactory for the material being packaged. The flange 6 may be taped to the outer wall of the body of the container in any suitable manner. It the container is not to be reused, the flange 6 may be heatsealed to the outer wall.

A rectangular container with a removable cover or container of other shape may be similarly constructed.

For an insulating material to be satisfactory for such usage, it is necessary that it combine the properties of lightness in weight (low density) and insulating value. Neither of these properties by itself is suiflcient to determine the adaptability of any particular insulating material for such use. For example, a material of low density and high K factor may often be substituted functionally for one of higher density and lower K factor. However, in usage such as that described here, the actual volume occupied by the insulator is also important.

It has been discovered that a combined function of such properties is valuable in determining the choice of insulator. Such a function has been termed the weight insulation factor and is represented by the product of density and K" factor. The units in which these two quantities are originally expressed will, of course, determine the magnitude of the values obtained by such a calculation.

Values obtained by such a calculation are illustrated in the table below for a number of common insulating materials:

K Factor, Density, B. t. 11. per Weight lbs. per sq. ft. per Insulation cu. ft. hr. per "F. Factor per in.

Glass fiber 2.5 0. 29 0. 73 Balsa wood 2. 2 0. 27 0. 59 5. 4 0. 25 1. 35 6. 0 0. 26 l. 56 9. 2 0. 26 2. 39 6. 0 0. 45 2.

1. 0 0. 23 0. 23 2. 6 0. 32 0. 83 2. 0 0. 16 0. 32 Cat-tails l. 0 0. 32 0. 32 Hard rubber sponge. 5. 0 0. 20 l. 00 Soft rubber sponge 7. 0 0. 27 1. 89 Expanded phenolic resin 7. 0 0. 28 l. 96 Expanded polyvinyl formaL 6. 0 0. M l. 44 Expanded polystyrene 3. 0 0. 22 0. 66

The above table includes materials which are satisfactory and materials whose weight limits their usefulness. The container of this invention is made with a material having a weight insulation factor of no more than 0.50 obtained by multip density in pounds per cubic foot with K factor expressed as B. t. u. per square foot per hour per degree Fahrenheit per inch.

Rubber hydrochloride film has generally beenfound more satisfactory than other membranous sheets, such as coated paper. cellophane,

3 tureproofed cardboard, aluminum or other light metal foil which might be coated with a heatsealing lacquer, and other plastic films, such as Velofilm, Saran film, polythene film, and vinyl films generally.

Such insulated containers can most advantageously be used for the transport of perishable items by air or other means of transport whereever weight and insulation are factors. An example is the transportation of sea. food from coastal to inland cities by air transport. The sea food is refrigerated and placed in the precooled container. Then by fiying at high altitudes where the temperature is low, long trips may be made without danger of the sea food being affected by being heated. It will retain its original low temperature with only very slight rise during many hours. Tropical fruits, flowers, etc., may similarly'be preserved while being transported to temperate climates. Still other uses of the conand rubber hydrochloride film, the container being cylindrical with a continuous layer of. insulation in the side and bottom walls or the body thereof and having a plug-type insulated closure, the insulation 01' said body and closure being about V inch thick with a weight insulation factor no greater than 0.50 .and being expanded urea-formaldehyde resin 01 such shape as to give form to the body and cover of the container, said insulation being enclosed in rubber hydrochloride film, the inner volume of the container ranging between a pint and a gallon.

LA VERNE E. CHEYNEY. ROBERT J. MccU'rcHEorI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,121,072 Corwin Dec. 15, 1914 1,641,030 Gross Aug. 30, 1927 1,691,178 Beaman Nov. 13, 1928 1,715,814 Brown June 4, 1929 1,952,448 Maloney Mar. 27, 1934 2,013,865 Sloan Sept. 10, 1935 2,076,295 Curs et al. Apr. 6, 1937 2,167,634 Calvert Aug. 1, 1939 

